Washing appliance water softener

ABSTRACT

A water softener particularly for use in a dishwasher. The water softener is located in the dishwasher water supply ( 238 ) between the primary supply valve and the wash chamber. The softener includes a resin container ( 207 ) with an ion exchange resin ( 290 ). Water supplied to the wash chamber optionally passes through the resin container ( 207 ). Regenerating brine is developed in a brine container ( 203 ). The brine container ( 203 ) is supplied manually with solid salt ( 270 ) and water diverted into the container from the main supply at an air break ( 201 ). In the regenerating cycle brine is delivered from the brine container ( 203 ) to the resin container ( 207 ) by a pump ( 206 ). The duty cycle of the pump ( 206 ) determines the degree of regeneration of the resin ( 290 ).

TECHNICAL FIELD

The present invention relates to a water softener for an automaticwashing machine and in particular but not solely to a dishwasher, whichincludes means for periodically regenerating the water softener.

BACKGROUND ART

It is well known that soft water is more effective than hard water inwashing clothes, dishes or other articles. To solve the problem of hardwater, small water softeners associated with either a washing machine ora dishwasher have been used to soften the water entering the machine

In water softeners a decalcifier which may comprise a resin containerexchanges both the calcium ions (Ca²⁺) and magnesium ions (Mg²⁺)contained in the water with sodium ions (Na⁺) contained in appropriateresins placed in the resin container. The resins are tiny beads,generally of an inert polymer structure.

Resins or other similar substances become exhausted after a certainusage time. Their ions Na⁺ to be exchanged with Ca²⁺ and Mg²⁺ containedin the water are consumed; as a result, water will still flow throughthe resin container but the hardness of the water is not reduced. Thisdrawback is prevented through a resin regeneration cycle. A brinesolution (NaCl) is introduced with the aim of regenerating the resin.

To adjust for different levels of water hardness EP219704 Milocco et aland EP433676 Bongini describe means for adjusting the mean path flow ofthe water through the resin container to adjust the level of watersoftening. Such arrangements are not easy to use and difficult tomanufacture.

A difficulty as to when to replenish salt is addressed by EP0351564 Jerget al using a mechanical float to indicate the presence or absence ofsalt. Mechanical float devices can stick and can give a wrong indicationresulting in the presence of salt being indicated when there is a lackof salt and the water entering the washing appliance is consequently notsoft enough.

Water softeners aim to keep the softness of water within desired bounds,in order to achieve this desire the resins in the resin container needto be kept charged with sodium ions (Na⁺). EP900765 Zucholl useselectrical conductivity sensors to detect the need to regenerate theresins. EP919178 Carli and EP1048776 Carli also use sensors to detectthe degree of exhaustion of the resins. Such sensors include thephysical volume of the resins, the pressure exerted by the resins on aswitch and the movement of an element contained within the resincontainer. Such devices add complexity to manufacturing water softeners.

Controlling the volume of brine flushed through the resin container canalso control the water softness. EP0367062 Fontana; EP545127 Milocco andEP0860140 Carli use water chambers to regulate the amount of brineflushed through the resins. The use of multiple water chambers adds tothe difficulty of manufacturing such water softeners and adjusting suchdevices.

DISCLOSURE OF THE INVENTION

It is an object of the present invention to provide a water softener foran appliance which at least goes some way towards overcoming the abovedisadvantages or at least provides the public with a useful choice.

In a first aspect the invention consists a washing appliance, which inuse is connected to a water supply, said appliance including a washchamber, a water softener and a programmed controller, said watersoftener comprising:

-   -   a resin container which contains a resin suitable for softening        water which receives water from said water supply and supplies        water to said wash chamber;    -   a brine container having an inlet for the supply of salt, an        inlet for the supply of water and an outlet;    -   a pump controlled by said programmed controller which receives        brine from said outlet of said brine container and pumps brine        through said resin container to thereby regenerate said resins        in accordance, with a duty cycle selected in accordance with the        supply water hardness.

In a second aspect the invention consists in a water softenercomprising:

-   -   a resin container which contains a resin suitable for softening        water which receives water from a water supply;    -   a brine container having an inlet for the supply of salt, an        inlet for the supply of water and an outlet;    -   a pump controlled by a programmed controller which receives        brine from said outlet of said brine container and pumps brine        through said resin container to thereby regenerate said resins        in accordance with a duty cycle selected in accordance with the        supply water hardness; and    -   an outlet for the supply of softened water;

In a third aspect the invention consists in a washing appliance which inuse is accommodated within a cavity in kitchen joinery or in afree-standing cabinet, said appliance comprising:

-   -   a wash system slidably mounted within said cavity in a manner        that it may be withdrawn horizontally for access thereto, said        wash system including:        -   an open top chamber adapted to accommodate items to be            washed and within which water is circulated;        -   means to supply water to said open top chamber including            water softener means associated with said open top chamber;        -   means for evacuating wash liquid from said chamber; and        -   a wash chamber closure that covers the open top of said open            top chamber on retraction of wash chamber into said cavity.

In a fourth aspect the invention consists in. a salt absence indicatorfor a brine container of a water softener, said salt absence indicatorcomprising:

-   -   a light source and light sensor located in a spaced apart        relationship at the bottom of said brine container, to define an        optical path there between, a controller receiving as an input        the output signal of said light sensor, and    -   an indicator light said indicator light being energised by said        controller upon receiving a signal from said light sensor when        the optical path between the light source and light sensor is        substantially transmissive.

In a fifth aspect the invention consists in a salt absence detectionindicator for a brine container of a water softener, said indicatorcomprising:

-   -   a light pipe extending between said brine container and a point        of visibility; and    -   a light located in the bottom of said brine container in        alignment with the bottom of said light pipe,    -   wherein rays from said light pass through said light pipe when        salt is absent from the space between the light and the end of        the light pipe

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the invention will now be described withreference to the accompanying drawings in which:

FIG. 1 is a diagrammatic longitudinal cross-section of a dishwasher ofthe preferred type to which the present invention relates,

FIGS. 2 and 3 show in diagrammatic form the plumbing and wiring systememployed in the dishwasher shown in FIG. 1,

FIG. 4 is a schematic diagrammatically illustrating a first embodimentof the water softener of the present invention,

FIG. 4A is a schematic diagrammatically illustrating a second embodimentof the water softener of the present invention with a hole in the supplyconduit supplying water to the brine tank,

FIG. 5 is a schematic diagrammatically illustrating a third embodimentof the water softener of the present invention with a float valve tocontrol water level in brine tank,

FIG. 6 is a schematic diagrammatically illustrating a fourth embodimentof the water softener of the present invention using an alternativefloat valve to control the water level in the brine tank,

FIG. 7 shows the light and light pipe for indicating the need toreplenish salt,

FIG. 8 shows the salt detector of the preferred water softener of thepresent invention,

FIG. 9 shows the salt replenishment device of the preferred watersoftener of the present invention,

FIG. 10 shows the detergent dispenser of the present invention.

MODES FOR CARRYING OUT THE INVENTION

The present invention is particularly but not solely adapted for use ina dishwasher of a type illustrated in FIG. 1. A wash chamber 101 withall wash components fitted and a front panel 102 are slidably mountedwithin a cavity 103. The wash chamber 101 has an open top 104 and isdrawn from the cavity 103 in the direction of arrow 105 to allow loadingand unloading of dishes and is retracted into the cavity 103 duringwashing. The wash and drain systems are fitted within wash chamber 101,including a motor, pumps and water supply circuit. Flexible connectingwiring and plumbing 107 couple the wash chamber 101 to the relevantterminations within the cavity 103 this can be best seen in FIGS. 2 and3. A lid 106 seals the chamber during washing of dishes. The watersoftener is located in a hollow wall 108 of the dishwasher.

The operation of the dishwashing machine is controlled by a programmedcontroller 110 of a known type.

The present invention is a water softener particularly for use in adishwasher. The water softener is located in the dishwasher water supplybetween the primary supply valve and the dishwasher chamber. Referringto FIG. 4 the softener includes a resin container 207 which contains anion exchange resin. Water supplied to the dishwasher chamber 101optionally passes through the resin container 207. Regenerating brine isdeveloped in a brine container 203. The brine container 203 is suppliedmanually with solid salt and water diverted from the main supply at anair break 201. In the regenerating cycle brine is delivered from thebrine container 203 to the resin container 207 by a pump 206. Theoperating cycle of pump 206 determines the degree of regeneration of theresin.

In the normal washing cycle water enters from a main flow control valvethrough inlet 238 and supply conduit 214. The supply conduit 214 leadsto an air break 201. An air break 201 is commonly provided to preventback flow. The flow passes through the air break 201 to a flow controlvalve 211. The flow control valve 211 is controlled by the appliancecontroller 110 and controls whether or not the water entering the washchamber 101 is softened or bypasses the resin container 207 andtherefore is not softened before entering the wash chamber 101.

When the water is to be softened the flow control valve 211 is inposition 225 and water flows via conduit 216 through the flow controlvalve 211 via conduit 217 to resin container 207. The water is softenedby the resins 290 in the resin container 207 and enters the dish washchamber 101 via conduit 219 and outlet 218. When water is not to besoftened the flow control valve 211 is in position 226 and the waterflows to the wash chamber 107 via conduit 219 and outlet 218. Waterflowing to the wash chamber 107 may pass through a detergent dispenser1001 shown in FIG. 10. The detergent dispenser inlet 1002 receives waterfrom outlet 218 and supplies water to the wash chamber 101 via detergentdispenser outlet 1003. The detergent dispenser 1001 is preferablymounted in a hollow vertical wall 108 of the appliance.

The programmed controller 110 may also switch the flow control valve 211during water supply to change the softness level of water supplied tothe wash chamber 107. The flow control valve 211 may be switched to mixunsoftened water and softened water to achieve the desired softnesslevel of water supplied to the wash chamber 107. Some cycles in thewashing program do not require soft water, for example the initialrinse, and the controller 210 can switch the flow control valve 211 toachieve the desired water softness for each cycle. In the preferredembodiment the follow control valve

The resin regeneration system using brine will now be described. Brineis produced in a brine container 203 by mixing water with salt.

To supply water to the brine container 203 an air break 201 in the watersupply circuit has an outlet orifice 202 bleeding off a proportion ofwater passing there through. The leakage through orifice 202 flows viaconduit 222 into the brine container 203. Water is supplied to the brinecontainer 203 using this leakage from outlet 202. This has the advantageof the elimination of active parts to supply water to the brinecontainer 203. Any excess fluid in the brine container 203 overflowsweirs 204 and 230 and enters the wash chamber 101 via a air breather231, or flows by a concealed conduit (now shown) to the dishwasher drainor sump. Excess leakage from the air break 201 is also channelled awayvia air breather 231 or flows by a concealed conduit (not shown) to thedishwasher drain or sump.

In an alternative seen in FIG. 4A a small hole 291 in conduit 215provides for the bleeding off of a small proportion of water. The hole291 is preferable in a high velocity point (a reduced section) so thehole can be larger and therefore easier to manufacturer. Excess leakagefrom the hole 291 overflows weir 230 and is channelled away via airbreather 231 or flows by concealed conduit (not shown) to the dishwasherdrain or sump. In any of the alternatives described water can besupplied to the brine container 203 via the leakage from the air break201, from a small hole in conduit 215 or using a combination of both.

Alternatively as seen in FIG. 6 a float valve 250 controls the fluidlevel in the brine container 203. Water supplied by conduit 222 isprevented from entering the brine container 203 by float valve 250 whenwater is at or above level 232. Excess leakage from the air break 201overflows weir 230 and is channelled away via air breather 231 or flowsby concealed conduit (not shown) to the dishwasher drain or sump.

In a further alternative as seen in FIG. 5 water flows through the airbreak 201 via conduit 251 into the brine container 203. A float valve250 prevents water flowing into the brine container 203 when the fluidlevel of the resin container is at or above level 232.

A salt filling orifice 208 is used to manually replenish the salt in thebrine container 203. The salt filling orifice 208 is plugged with a capor bung 224 when not opened for refilling. The fluid in the brinecontainer 203 is at a level 232 below the filling orifice 208.

A suitable device 901 shown in FIG. 9 is used to replenish the salt. Thedevice is shaped so that the salt granules flow freely into the brinecontainer 203. The shape is also necessary because the salt fillingorifice 208 of the brine container 203 is in a hollow vertical wall 108of an appliance.

As the brine container 203 is filled with salt, the level of water inthe brine container is maintained by having the excess fluid overflowthe weirs 204 and 230. This has the advantage that the device 901 usedto refill the salt does not get wet nor is salt washed away and wasted.Any fluid overflowing the weirs 204 and 230 comes from the top of thebrine container 203, and will have a lower content of dissolved salt.

Alternatively as seen in FIGS. 5 and 6 the fluid level in the brinecontainer 203 rises when salt is added but because of the use of thefloat valve 250 no fluid is added until the level is below the floatvalve level. Because the fluid level 232 is below the salt level 270when salt is added the fluid level will rise but not sufficiently tooverflow.

Air vents 234, 235 allow for the removal of air by conduit 236.

The presence of solid salt in the brine container 203 is sensed using asalt sensor 209. The sensor 207 can be seen in FIG. 8. The salt sensor209 includes a light 212 and light sensor such as a photo transistor 213positioned at the bottom of the brine container 203. The presence ofsolid salt can be detected because solid salt deflects light reducingthe intensity of light received at light sensor 213 from light 212, toan extent that the presence of solid salt can be differentiated from theabsence of solid salt. The light sensor 213 output signal is supplied toan analogue input part of controller 110.

A salt empty indicator 210 provides a salt empty indication to a user. Alight emitting diode can be used as the indicator. It is energised bythe programmed controller. Timing when the salt empty indicator 210 isswitched on can be altered relative to when the salt sensor 209 firstdetects an absence of solid salt. This delay can take into account thepresence of dissolved salt in the brine container 203. Alternatively thesalt empty indicator can be switched on directly by a salt sensorcontrol circuit not shown.

The salt indicator 210 is in the bung 224 of the brine container 203. Inthe preferred embodiments seen in FIG. 7 a light 290 shining indirection of arrows 291 shines through light pipe 292 and as seen by auser as indicator 210.

In a further alternative seen in FIGS. 5 and 6 the salt sensor 209 isreplaced with a light 260 and a light pipe 262 the light shining throughthe light pipe 262 only when solid salt is absent. When solid salt ispresent light is deflected and does not shine through the light pipe. Agap 261 exists between light 260 and light pipe 262 and when solid saltis present the salt deflects the light.

An outlet 205 in the brine container 203 feeds brine to pump 206 via aconduit 221. The brine flowing out of the brine container 203 is pumpedthrough resin container 207 replenishing the resins 290 which are usedto reduce the hardness of the water. Mesh 240 prevents solid salt frombeing pumped through the resin container 207. Excess fluid pumpedthrough the resin container 207 is drained away via conduit 219 andoutlet 218 to the dishwasher drains. The pump 206 is directly controlledby the programmable controller 110 and the quantity of fluid deliveredto the resin container 207 is controlled by controlling the duty cycleof the pump. The pumping cycle can be adjusted via a keypad 111 attachedto the controller 110.

The amount of brine that is pumped through the resins 290 affects theoverall replenishment of the resins 290. How replenished the resins 290are, affects the ability of the resins 290 to soften the water. The morereplenished the resins 290 are the greater the difference between thewater entering the resin container 207 via conduit 217 and the waterleaving the resin container 207 via conduit 219 and outlet 218 will be.A desired water softness level can be achieved by adjusting the amountof brine replenishing the resins 290 and this can be adjusted byaltering the duty cycle of the brine pump 206.

In a resin 290 replenishment cycle, flow control valve 211 is inposition 226 and the brine is pumped by the brine pump 206 from thebrine container 203 into resin container 207. Water leaving the resincontainer 207 as the brine is pumped in will pass through conduit 219and outlet 219 into the dishwasher chamber 101 and be drained away.

In an alternative embodiment the flow control valve 211 would be inposition 225 and a percentage of water leaving the resin container 207would pass via conduit 215 leakage 202 and conduit 222 into the saltcontainer 203. A percentage would still pass into the wash chamber 101and be drained away. This has the advantage of reducing water usage.

Using the brine pump 206 the regeneration of the resins 290 in the resincontainer 207 can happen even when the resin container 207 is softeningwater for supply to the wash chamber 101.

This invention may also be said broadly to consist in the parts,elements and features referred to or indicated in the specification ofthe application, individually or collectively, and any or allcombinations of any two or more of said parts, elements or features, andwhere specific integers are mentioned herein which have knownequivalents in the art to which this invention relates, such knownequivalents are deemed to be incorporated herein as if individually setforth.

1. A washing appliance, which in use is connected to a water supply,said appliance including a wash chamber, a water softener and aprogrammed controller, said water softener comprising: a resin containerwhich contains a resin suitable for softening water which receives waterfrom said water supply and supplies water to said wash chamber; a brinecontainer having an inlet for the supply of salt, an inlet for thesupply of water and an outlet; a pump controlled by said programmedcontroller which receives brine from said outlet of said brine containerand pumps brine through said resin container to thereby regenerate saidresins in accordance, with a duty cycle selected in accordance with thesupply water hardness.
 2. A washing appliance as claimed in claim 1including a flow directing valve connected to said water supply havingone outlet feeding said resin container, and the second outlet feedingsaid wash chamber, said flow directing valve being controlled by saidcontroller to provide a flow to one or both of said outlets so as toprovide a blend of supply water and softened water to said wash chamber.3. A washing appliance as claimed in claim 2 wherein said controllercontrols said flow directing valve so as to determine the ratio of thewater components of said blend to achieve a desired softness of water insaid wash chamber.
 4. A washing appliance as claimed in either of claim2 or claim 3 wherein said flow directing valve is a two-way solenoid. 5.A washing appliance as claimed in claim 1 including a detergentdispenser wherein water supplied to said wash chamber by said watersoftener passes through said detergent dispenser.
 6. A washing applianceas claimed in claim 1 wherein said water softener is mounted in a hollowwall of said washing appliance.
 7. A washing appliance as claimed inclaim 1 wherein said brine container additionally has an overflow weirfor the maintenance of a maximum water level in said brine container. 8.A washing appliance as claimed in claim 7 wherein said overflow weirspillage is coupled directly to an appliance drain.
 9. A washingappliance as claimed in claim 7 wherein said overflow weir spillage iscoupled directly to an appliance sump.
 10. A washing appliance asclaimed in claim 1 wherein said water level in said brine container iscontrolled by a float valve.
 11. A washing appliance as claimed in claim1 wherein said water softener has a user indicator to indicate theabsence of salt.
 12. A washing appliance as claimed in claim 111 whereinsaid indicator comprises a light and a light pipe.
 13. A washingappliance as claimed in claim 12 wherein said light pipe extends betweensaid brine container and a point of visibility said light is located inthe bottom of said brine container in alignment with the bottom of saidlight pipe, wherein rays from said light pass through said light pipewhen solid salt is absent from the space between the light and the endof the light pipe.
 14. A washing appliance as claimed in claim 11wherein said indicator comprises an indicator light energised when theabsence of solid salt has been detected using a light and light sensorlocated in said brine container.
 15. A washing appliance as claimed inclaim 14 wherein energising of said indicator light is controlled bysaid programmed controller.
 16. A washing appliance as claimed in claim11 wherein said light source and said light sensor are located in aspaced apart relationship at the bottom of said brine container, todefine an optical path there between, a controller receiving as an inputthe output signal of said light sensor and said indicator light beingenergised by said controller upon receiving a signal from said lightsensor when the optical path between said light source and said lightsensor is substantially transmissive.
 17. A washing appliance as claimedclaim 15 wherein said controller can delay energising said indicatorlight for a delay period after absence of solid salt is detected.
 18. Awashing appliance as claimed in claim 1 wherein said appliance in use isaccommodated within a cavity in kitchen joinery or a free-standingcabinet, and additionally comprises: a wash system slidably mountedwithin said cavity in a manner that it may be withdrawn horizontally foraccess thereto, said wash system including: an open top chamber adaptedto accommodate items to be washed and within which water is circulated;means for evacuating wash liquid from said chamber; and a wash chamberclosure that covers the open top of said open top chamber on retractionof wash chamber into said cavity.
 19. A washing appliance as claimed inclaim 1 said washing appliance is a dishwasher.
 20. A water softenercomprising: a resin container which contains a resin suitable forsoftening water which receives water from a water supply; a brinecontainer having an inlet for the supply of salt, an inlet for thesupply of water and an outlet; a pump controlled by a programmedcontroller which receives brine from said outlet of said brine containerand pumps brine through said resin container to thereby regenerate saidresins in accordance with a duty cycle selected in accordance with thesupply water hardness; and an outlet for the supply of softened water.21. A water softener as claimed in claim 20 including a flow directingvalve connected to said water supply having one outlet feeding saidresin container, and the second outlet feeding said outlet for thesupply of softened water, said flow directing valve being controlled bysaid controller to provide a flow to one or both of said outlets so asto provide a blend of supply water and softened water.
 22. A watersoftener as claimed in claim 21 wherein said controller controls saidflow directing valve so as to determine the ratio of the watercomponents of said blend to achieve a desired softness of water.
 23. Awater softener as claimed in claim 21 wherein said flow directing valveis a two-way solenoid.
 24. A water softener as claimed in any one ofclaims 20 to 23 wherein said brine container additionally has anoverflow weir for the maintenance of a maximum water level in said brinecontainer.
 25. A water softener as claimed in claim 20 wherein saidsupply of water to said brine container is controlled by a float valve.26. A water softener as claimed in claim 20 wherein said water softenercontainer has an indicator to indicate the absence of salt.
 27. A watersoftener as claimed in claim 26 wherein said indicator comprises a lightand a light pipe.
 28. A water softener as claimed in claim 27 whereinsaid light pipe extends between said brine container and a point ofvisibility said light is located in the bottom of said brine containerin alignment with the bottom of said light pipe, wherein rays from saidlight pass through said light pipe when solid salt is absent from thespace between the light and the end of the light pipe.
 29. A watersoftener as claimed in claim 26 wherein said indicator comprises anindicator light energised when the absence of solid salt has beendetected using a light and light sensor located in said brine container.30. A water softener as claimed in claim 29 wherein energising of saidindicator light is controlled by said programmed controller.
 31. A watersoftener as claimed in claim 29 wherein said light source and said lightsensor are located in a spaced apart relationship at the bottom of saidbrine container, to define an optical path there between, a controllerreceiving as an input the output signal of said light sensor and saidindicator light being energised by said controller upon receiving asignal from said light sensor when the optical path between said lightsource and said light sensor is substantially transmissive.
 32. A watersoftener as claimed in claim 30 wherein said controller can delayenergising said indicator light for a delay period after absence ofsolid salt is detected.
 33. A washing appliance which in use isaccommodated within a cavity in kitchen joinery or in a free-standingcabinet, said appliance comprising: a wash system slidably mountedwithin said cavity in a manner that it may be withdrawn horizontally foraccess thereto, said wash system including: an open top chamber adaptedto accommodate items to be washed and within which water is circulated;means to supply water to said open top chamber including water softenermeans associated with said open top chamber; means for evacuating washliquid from said chamber; and a wash chamber closure that covers theopen top of said open top chamber on retraction of wash chamber intosaid cavity.
 34. A washing appliance as claimed in claim 33 including adetergent dispenser wherein water supplied to said wash chamber by saidwater softener passes through said detergent dispenser.
 35. A washingappliance as claimed in either of claim 33 or claim 34 wherein saidwater softener means are mounted in a hollow wall of said washingappliance.
 36. A washing appliance as claimed in claim 33 wherein saidwashing appliance is a dishwasher.
 37. A salt absence indicator for abrine container of a water softener, said salt absence indicatorcomprising: a light source and light sensor located in a spaced apartrelationship at the bottom of said brine container, to define an opticalpath there between, a controller receiving as an input the output signalof said light sensor, and an indicator light said indicator light beingenergised by said controller upon receiving a signal from said lightsensor when the optical path between the light source and light sensoris substantially transmissive.
 38. A salt absence indicator as claimedin claim 37 wherein said controller includes means for delayingenergising said indicator light for period after receiving said signalfrom said light sensor corresponding to said optical path beingtransmissive.
 39. A salt absence detection indicator for a brinecontainer of a water softener, said indicator comprising: a light pipeextending between said brine container and a point of visibility; and alight located in the bottom of said brine container in alignment withthe bottom of said light pipe, wherein rays from said light pass throughsaid light pipe when salt is absent from the space between the light andthe end of the light pipe.
 40. (canceled)
 41. (canceled)
 42. (canceled)